They HAVE announced one as Jade Empire, but everything about the other game is ONLY rumors as of yet. I've been checking out the official site, and unlike Rare and Nintendo, they actually CARE about giving accurate data there. I'd think they would know if they were in fact making a second KOTOR game. As of yet, they haven't announced a thing.
"On two occasions, I have been asked [by members of Parliament], 'Pray, Mr. Babbage, if you put into the machine wrong figures, will the right answers come out?' I am not able to rightly apprehend the kind of confusion of ideas that could provoke such a question." ~ Charles Babbage (1791-1871)
KOTOR 2 was announced last year, and it's being developed by Obsidian, not Bioware. Some of the people that worked on Planescape are at Obsidion, so it's in good hands.
... I went back to Baldur's Gate II, after ... um, being intimidated by how long it is and how many options you have ... I think I've played like 6-8 hours in the last two days and have only made a bit of progress. Not that I'd expect much else from the game. :)
Oh, and Obsidian, huh? That's okay, Obsidian is made up of ex-Black Isle guys (like Troika and InXile... and Bioware in a way because Black Isle was a huge influence in Bioware's RPGs...).